telnet: connect to address IPV6 Connection refused
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- Posts: 35
- Joined: 2020/05/05 19:44:15
Re: telnet: connect to address IPV6 Connection refused
For my understanding it is a IPv6 issue.
Re: telnet: connect to address IPV6 Connection refused
I suspect you have an external firewall in front of your machine that's blocking the connections.
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke
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- Posts: 35
- Joined: 2020/05/05 19:44:15
Re: telnet: connect to address IPV6 Connection refused
No - no external firewall.
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- Joined: 2020/05/05 19:44:15
Re: telnet: connect to address IPV6 Connection refused
Please note that the following services are open:
root@kamet:~> nmap -6 makalu.akadia.com
Starting Nmap 6.40 ( http://nmap.org ) at 2021-04-03 09:00 MEST
Nmap scan report for makalu.akadia.com (2a0258e2::1)
Host is up (0.0066s latency).
Not shown: 996 closed ports
PORT STATE SERVICE
22/tcp open ssh
53/tcp open domain
80/tcp open http
443/tcp open https
MAC Address: 8C:59:C3:D1:39:8A (Unknown)
Nmap done: 1 IP address (1 host up) scanned in 2.91 seconds
But not smtp - why not, I do not understand
root@kamet:~> nmap -6 makalu.akadia.com
Starting Nmap 6.40 ( http://nmap.org ) at 2021-04-03 09:00 MEST
Nmap scan report for makalu.akadia.com (2a0258e2::1)
Host is up (0.0066s latency).
Not shown: 996 closed ports
PORT STATE SERVICE
22/tcp open ssh
53/tcp open domain
80/tcp open http
443/tcp open https
MAC Address: 8C:59:C3:D1:39:8A (Unknown)
Nmap done: 1 IP address (1 host up) scanned in 2.91 seconds
But not smtp - why not, I do not understand
Re: telnet: connect to address IPV6 Connection refused
There is zero point in running nmap against the server from the server. As I already said, when you do that, the packets appear to come from localhost and are allowed.
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke
Re: telnet: connect to address IPV6 Connection refused
Set tcpdump to listen smtp-port on makalu. Then attempt connect from kamet to makalu.
The obvious results are:
The obvious results are:
- Nothing comes to makalu. Problem is not in makalu
- Makalu replies with reject
- Makalu replies ok, but not with IPv6/correct route
- Successful connection
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- Posts: 35
- Joined: 2020/05/05 19:44:15
Re: telnet: connect to address IPV6 Connection refused
Sorry, I do not know what to to with tcpdump.
Re: telnet: connect to address IPV6 Connection refused
yum install tcpdump
tcpdump port 25 -i $interface -n -nn -l
Amend $interface to reflect your external interface name. Ctrl-C to exit.
tcpdump port 25 -i $interface -n -nn -l
Amend $interface to reflect your external interface name. Ctrl-C to exit.
The future appears to be RHEL or Debian. I think I'm going Debian.
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke
Info for USB installs on http://wiki.centos.org/HowTos/InstallFromUSBkey
CentOS 5 and 6 are deadest, do not use them.
Use the FAQ Luke
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- Posts: 35
- Joined: 2020/05/05 19:44:15
Re: telnet: connect to address IPV6 Connection refused
Thank you all !
I tried tcpdump on makalu.akadia.com
tcpdump -i enp0s31f6 -vv dst makalu.akadia.com -n -nn -l (Port cannot be specified)
Then I try to connect from kamet:
telnet makalu.akadia.com 25
No output from tcpdump.
Regards Martin Zahn from Switzerland
I tried tcpdump on makalu.akadia.com
tcpdump -i enp0s31f6 -vv dst makalu.akadia.com -n -nn -l (Port cannot be specified)
Then I try to connect from kamet:
telnet makalu.akadia.com 25
No output from tcpdump.
Regards Martin Zahn from Switzerland
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- Posts: 35
- Joined: 2020/05/05 19:44:15
Re: telnet: connect to address IPV6 Connection refused
Here the fully specified tcptump
root@makalu:~> tcpdump -i enp0s31f6 -vv dst makalu.akadia.com -n -nn -l and port 25
tcpdump: listening on enp0s31f6, link-type EN10MB (Ethernet), capture size 262144 bytes
CTRL-C
Again no connection from kamet.
What does that mean ?
root@makalu:~> tcpdump -i enp0s31f6 -vv dst makalu.akadia.com -n -nn -l and port 25
tcpdump: listening on enp0s31f6, link-type EN10MB (Ethernet), capture size 262144 bytes
CTRL-C
Again no connection from kamet.
What does that mean ?